MSG–BSA Freezer Medium for the Storage of Bacteria

For a final volume of 500 mL of 10% (w/v) MSG 10% (w/v) BSA:

• 1. Add 50 g of monosodium glutamate (l-glutamic acid monosodium salt hydrate, MSG) (Sigma-Aldrich G1626) and 50 g of bovine serum albumin (BSA) to 300–400 mL of H₂O.

• 2. Stir to dissolve.

• 3. Bring the volume to 500 mL with H₂O.

• 4. Filter-sterilize the solution.

• 5. Make aliquots of 40–50 mL.

• 6. Store for up to several months at 4°C, or, for longer-term storage, freeze at −20°C.

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